Google Phone GPS Misses by a Mile

March 30, 2009, 6:27 pm

Google Phone GPS Misses by a Mile

By Roy Furchgott

It’s a bit of a left-handed compliment, but I am shocked when Google fails at anything – after all, it has come out with one remarkable bit of software after another.

So I am especially surprised when it fails in fields it is most known for. I’ve already railed about the unbelievably lackluster search engine on the Android Marketplace. C’mon guys, you OWN search.

But equally baffling is how poor the GPS is on the G1 Google Phone running Android. It can get relatively close to my position when outdoors in an open space, but in city canyons or indoors it is off by a literal mile. Let’s hope no one is relying on the phone to direct emergency services.

It gets even more quizzical when you consider that many Android apps using the G1’s GPS are highly accurate. What gives?

It helps to understand how smartphone GPS works. Most phones use a combination of data to pinpoint your location. Proper GPS works best in open areas, say out in the country, where there is unimpeded view of the sky. But in cities it’s tougher to get a clear shot at the satellites, and indoors it’s impossible. So the phones also look for nearby Wi-Fi sites and cell towers.

They don’t triangulate by reading the strength of the Wi-Fi and cell tower signals, as is commonly thought. Companies, such as Skyhook, hire people to drive around with computer rigs that detect Wi-Fi signals and then automatically mark the location (the same way Google collects and compiles its Street View shots, by the way). That information becomes part of a database. When you make a call, it looks at which Wi-Fi sites and towers you are near, then looks in the database for where those are located, and then approximates where you are.

Many app developers use Skyhook’s database, which includes 100 million Wi-Fi sites and 400,000 cell towers in 32 countries. It’s even one of the sources Apple uses for its generally accurate GPS services.

It seems that there are only two possibilities for Google’s inaccuracy. Either Google’s Wi-Fi and tower data is inferior, or its ability to crunch the data is. Google declined to comment, but either problem should be easily fixed – hey, other developers have found solutions. Maybe Google should to partner up or buy someone out?